- 行业: Earth science
- Number of terms: 93452
- Number of blossaries: 0
- Company Profile:
Founded in 1941, the American Congress on Surveying and Mapping (ACSM) is an international association representing the interests of professionals in surveying, mapping and communicating spatial data relating to the Earth's surface. Today, ACSM's members include more than 7,000 surveyors, ...
(1) That ellipse, on an ellipsoid representing the Earth, in which a plane through the center of the ellipsoid and perpendicular to the shortest axis cuts the surface. If the ellipsoid is an oblate spheroid (oblate rotational ellipsoid), the ellipse is a circle. (2) That circle, on an oblate rotational ellipsoid, midway between the ends of the rotational axis. The geodetic equator is the line on which geodetic latitude is 0<sup>o</sup> and from which geodetic latitudes are reckoned, north and south, to 90<sup>o</sup> at the poles. The plane of the geodetic equator cuts the celestial sphere in a line coinciding with the celestial equator if the axis of the ellipsoid is parallel to the Earth's axis of rotation.
Industry:Earth science
The right to enter property temporarily to make surveys and investigations for proposed improvements.
Industry:Earth science
A single, indivisible entity of an optical system, usually a lens. It is a single piece of optical material, such as a lens, mirror or prism, which is designed to reflect, refract or diffract light in a specified way. The material between lenses, mirrors, etc. , may itself be an optical element in certain optical systems.
Industry:Earth science
A person who makes an entry of land under the public-land laws of the USA.
Industry:Earth science
The equal-altitude method (1) of determining azimuth, using the Sun as the observed body. Horizontal angles are measured from a southerly reference-point to the Sun's limbs at an identical vertical angle; if measured to the right limb before noon, it should be measured to the left limb after noon. The same limb should be observed in vertical angles. The average of the two horizontal angles, with small correction for the change in the Sun's declination during the interval from a. M. to p. M. readings, gives a resulting, horizontal angle to the meridian.
Industry:Earth science
An equation in rectangular, Cartesian coordinates, giving the quantity z as the sum of an arbitrary number of quadratic functions of x, y and z. The quadratic functions usually have the form (- x<sub>k</sub>)² + (y - y<sub>k</sub>)² + (z - z<sub>k</sub>)² , in which x<sub>k</sub>, y</sub>k, z<sub>k</sub> are constants. They have been used in surface fitting.
Industry:Earth science
The amount of energy given off by a body in unit time, relative to the amount per unit time given off by a black body at the same temperature. It is usually expressed as a positive number between 0 and 1.
Industry:Earth science
A photographic emulsion having a sensitivity to color similar to that of the human eye, but producing black and white pictures only.
Industry:Earth science
